Tester for laundry process and laundry process employing the same



June 18, 1963 L. F. LUECHAUER 3,094,373-

TESTER FOR LAUNDRY PROCESS AND LAUNDRY PROCESS EMPLOYING THE SAME FiledDec 4, 1961 Louis F. UECHA UER LINVENTOR. W

ATTORNEYS United States Patent 3,094,373 TESTER FOR LAUNDRY PROCESS ANDLAUNDRY PROCESS EMPLOYING THE SAME Louis F. Luechauer, P.O. Box 54,Sugarhouse Station, Salt Lake City, Utah Filed Dec. 4, 1961, Ser- No.156,753 17 Claims. (Cl. 8-137) This invention relates to means fordetermining the physico-chemical and chemical parameters which controlthe process of laundering and to laundering process employing suchmeans.

It is an object of this invention to provide the laundryman with meansand procedures to determine the conditions existing in the various stepsof his washing operation, in order that he may control the laundryprocess to reach his objective by fixing the parameters of thelaundering process which control the rate and intensity of the chemicaland physico-chemical changes occurring in the laundering process.

The laundering process in general involves, in various combinations, asudsing step, wherein the wash is subjected at an elevated temperatureto an alkaline water dispersion of a surfactant such as a detergent,which may be ordinary fatty acid soap or a synthetic detergent; it isthen followed by a rinse step and, depending on the nature of the soiledwash, it may be subjected to a souring-olf step by treatment with asolution at an acid pH. It may, however, be subjected to a bleachingstep prior to the souring step.

The parameters which affect the laundering process are alkaliconcentration and temperature and time in the sudsing step, taken inrelation to the amount of soil in the wash, the effectiveness of therinse steps, the alkalinity and bleach concentration, and the time andtemperature in the bleach step, and the efiectiveness of the souringstep.

It is an object of my invention to provide a testing means and testingprocedure whereby the magnitude and effectiveness of the aforesaidparameters may be determined, and the laundering process controlled toproduce the most economical washing operation.

The testers of my invention consist of yarn or cloth dyed with dyes, andpaper colored by pigments, which undergo color changes which areindicative of the laundering parameters, and testers which areindicative of the duration of the laundering steps or of the degree ofmechanical agitation.

It is an object of my invention to provide a tester which will permitthe laundryman to determine if the operation parameters in the varioussteps have been properly adjusted to the service which they are toperform in the laundering operation and to isolate the parameters whichare improper in the various steps of the laundering operation. For thispurpose, it is an object of my invention to provide a tester comprisedof a number of detectors formed of dyed textile materials, which may becloth or yarn dyed with dyes which, by their color changes, indicate therelative intensity of the factors of concentration of the chemicals andthe time and temperature employed in the various steps and theeificiency of the various steps of the process.

Other detectors may be employed by using sensitive pigments for thepurposes to the described below.

By using these detectors in combination, the relative influence of thevarious process parameters which combine to produce the launderingelfects in the various stages of the process may be segregated from eachother.

The laundry industry, for many years, was devoted primarily to thelaundering of household items sent in by customers. The advent of homewashers in almost every ice household shifted the emphasis to rentalplants who supply their own linens to home, hotels, restaurants, beautyshops, industrial plants, and the like. Customers who rent linen oftenabuse it badly. This poses a two-pronged problem for the rentaloperator. He must use formulas that are sufiiciently severe to removethe stains, and at the same time avoid undue damage to the linen whichhe owns. Linen replacement expense often averages onefourth of the totalincome, and demands careful attention in achieving adequate launderingWithout undue damage to the linen.

The testers of my invention are designed to assist the laundry toachieve its objectives with economy.

THE LAUNDERING PROCESS The washing formulas recommended by the ALL.(American Institute of Laundering) for laundering of household andpersonal linen, included a series of sudsing operations, usuallyinvolving alkali and :soap followed by a bleaching step, then four orfive rinses. Starting temperatures were usually low (in the range), andsubsequent sudsings seldom exceeded The linen supply operator found itnecessary to use higher temperatures; and instead of using three of fourten minute. sudsing steps, one longer sudsing at higher temperaturesalong with a fairly high concentration of alkali proved to be much moredesirable. As a rule, two to four flushing steps were required to removesufficient amounts of loose soil for adequate bleaching intensity.

Linen supply operators found it advantageous to classify the twenty orso different items which they normally furnished into the categories oflight, medium and heavy soil. They also found that it was not feasibleto achieve 100% stain removal in even heavy soil or severe washingformulas. Hence, stained items are accumulated and are re-w-ashed withformulas commonly referred to as a stain treat formula.

Laundrymen also use such terms as mild, normal and severe to describealkaline and/or bleaching intensities.

THE NATURE OF SOILS ENCOUNTERED IN LAUNDRY OPERATIONS The following aregiven not as a limitation of my invention or of the practice followed inlaundries, but for the purpose of orientation and explanation for abetter understanding of my invention.

Light S0il.Lightly soiled items in a linen supply plant are those whichare neither badly stained nor contain appreciable quantities of loosesoil. Sheets used by hotels are considered light soil. In many casestowels from barber shops fall into this same category. Sometimes it isunnecessary to use bleach to achieve adequate whiteness. Weight of thesoiling material in items in this classification is negligible; forexample, approximately one-half pound of dry soil (0.2%) per 300-poundload may be taken as typical.

Medium SoiL-Medium soil in a linen supply plant usually consists ofwaitress dresses, towels from beauty shops, andin some cases-napkinsfrom restaurants. Weight of the soiling material in items in thisclassification is greater than in the light soil, above. Thisclassification will also contain some stains which require strongercleaning solutions; for example, approximately five pounds of dry soil(2.0%) per SOD-pound load may be taken as typical.

Heavy Soil.ltems falling into this category not only contain stains, butappreciable amounts of loose soil which must be flushed or rinsed out ofthe washing machine in order to avoid gray work. Items in thisclassification would be aprons from butcher shops; towels fromrestaurants; and swipes that are used for clean-up purposes. Weight ofthe soiling material in this category will be,

for example, approximately 30 pounds of dry soil (10.0%) per 300-poundload, as a typical figure.

Stained or Re-Wash Loads.Formulas used in this category must be severeenough to remove the stains that it was not feasible to remove in theoriginal laundering by any of the formulas shown above. There issubstantially no loose soil present, and treatments suitable forhandling these items would be aimed primarily at removing stubbornstains. One of the most common stubborn stains occurring in rentalplants is mildew.

Industrial Soil.-Some laundries specialize in handling industrial itemssuch as towels and coveralls from garages and industrial plants. Theseitems contain oily soil rather than fatty soil; and both formulas andsupplies used on them are quite different from that of the ordinaryrental plant. Weight of the soiling material in this classification isfar greater than in any other; for example, approximately 100 pounds drysoil (30.0%) per 300-pound load may be taken as typical. At this pointit may be best to understand the terms insufficient, normal andexcessive, as employed in laundry practice.

Any quantity less than that normally used on light soil is consideredinsufficient. The concentrations used on medium soil are consideredexcessive for light soil.

For example, alkali concentrations for light soil and medium soil may betypically as follows:

Table 1 7 Light soil, Medium percent soil. percent Tnsnfficient 0.05 0.1 Normal O. 0. 2 Excessive 0. 0. 3

These figures are intended for orientation and explanatory purposes, andnot as limitations of the percentage and ranges which may be encounteredin laundry operations.

TYPICAL LAUNDERING FORMULAS Numerous alkalies may be used by commerciallaundries. Sodium or-thosilicate or its equivalent is most common. Thereare extreme variations in the concentrations used by various plants.Also, pH values change during a sudsing operation of a washing formula.The quantity of fatty soil which may be present has a decided effectupon them. For example, variations in alkaline concen- (nations (andchanges in pH values most often occurring in commercial laundry practiceare shown below:

The above percentages or pH ranges are those most commonly employed forthese services in commercial laundries, although variations therefromare also, but less frequently, employed. These figures, therefore, areincluded for orientation and explanatory purposes and not as alimitation of the percentages and ranges which may be encountered inlaundry operations.

Many laundries use mixtures of polyphosphates and alkalies. Mixturesthat contain phosphates are considered mild alkalies. Anhydrousmetasilicate is also considered a mild alkali. Orthosilicate, on theother hand, is considered a strong alkali. Few plants use caustic sodaunless it is buffered with soda ash, phosphate, etc. In the discussionwhich follows, the following table will help:

Polyphosphates are considered non-alkaline.

Metasilicate is considered a mild alkali.

Orthosilicate is considered the normal alkali.

Caustic soda is considered a strong alkali.

The table below shows the time and temperatures often used on suds andbleach baths. As a rule, flushes are required to remove loosened soilprior to the bleach bath. Flushes are usually three minutes in duration,and the number used may vary from one to five or six.

Table III Temperature (deg) Time (min) Type of formula Suds Bleach SudsBleach Washing temperatures in the 200 to 210 range are consideredexcessive by most plants. Many plants use washing temperatures as low as145 to in washing light soil. Sudsing temperatures below 145 aregenerally considered inadequate for either soil removal or sanitaryaspects of laundering.

Formula times shown above are those considered average in most plants,but times of treatment will depend on objectives desired and the otherparameters of the laundering process, as described above.

Formula times may be varied also due to the type or kind of washer used.Those shown above are those most often encountered with open pocketwashers. This type of washer is one without horizontal partitions, andwith a rotational speed usually or 21 revolutions per minute.

The bleach concentration data most often encountered, as shown below, isthe initial concentration in the washer. During an eight minute bleachbath on many formulas the final concentration is often in the range of10 to 20 parts per million. The pH of the bleach bath changes during ableaching step due to the release of hypochloric acid. The range ofvalues generally found is 9.8 to 10.5. Low pH bleaching, as used by theaverage laundryman, would indicate values near pH 7. High pH bleachingin most plants would be considered values in the neighborhood of 11.5.

bath, percent None or 0.002 0. 005 0. 01 0. 1 0. 01

Ham-n... 000. 0 cacao-1H0 Industrial Throughout this specification,except as separately stated, bleach is understood to be hypochlorite,usually added in the form of sodium hypochlorite.

As in the previous tables, these percentages and pH values are thosemost commonly employed in laundry operations, but they will varydepending on the objectives desired and other parameters, as describedabove in connection with the other tables.

Illustrative of the formulas employed in laundering, the following aregiven as examples of typical formulas for the uses indicated. It will beunderstood that deviations and alternative formulas may be employed, andthe formulas given are for illustration and explanatory purposes. In thefollowing Tables V-VIII, percentages are given as percent by weight.

5 Table V NO. 1FORMULA FOR LIGHT SOIL [Standard size 42 x 84 open pocketwasher] Water Temp,

Time,

Operation level, minutes inches (1a) Flush, bloody loads 6-8 120 3 (1)Flush 6-8 Hot 3 (2) Alkali suds: Orthosilicate cone.

0.1%, soap concentration 0.02%. 3 175 10 (3) Rinse 12 1 Hot 3 (4) Rinse12 130 3 (5) Rinse 12 120 3 (6) Rinse 12 Cold 3 (7) Sour, ammoniumsilicofluoride cone. 0.02% Cold 1 Temperatures are not critical, usually160.

Table VI NO. 2-FORMULA FOR MEDIUM SOIL [Standard size 42 x 84 openpocket washer] Water Temp, Time, Operation level, F. minutes inches (1a)Flush, bloody loads 6-8 120 3 (1) Flush 6-8 Hot 3 (2) Alkali Suds:Orthosilicate cone.

0.2%, soap concentration 0.06%- 3 185 15 (3) Flush 12 150 3 (4) Flush 12150 3 (5) Suds bleach: Soap concentration 0.01%, bleach concentration0.005 X 6 145 8 (6) Rinse 12 145 3 (7) Rlnse 12 130 3 (8) Rinse 12 120 3(9) Rinse 12 Cold 3 (10) Sour,

cone. 0.02% 6 Cold 5 1 As sodium hypochlorite.

Table VII NO. 3-FORMULA FOR HEAVY SOIL [Standard size 42 x 84 openpocket Washer] Water Temp, Time, Operation level, F. minutes inches (1)Flush (Water only) 12 Hot 3 (2) Alkali Suds: Orthosillcate conc.

0.4%, soap concentration 0.2%"- 3 195 12 Hot 3 12 Hot 3 12 150 3 (6)Flush, optional 12 150 3 (7) Suds Bleach: Soap concentration 0.1%,bleach concentration 0.01%L 6 145 8 (8) Rinse 12 145 3 (9) Rinse 12 1303 (10) Rinse 12 120 3 (11) Rinse 12 Cold 3 (l2) Sour, ammoniumsihcofluoride cone. 0.02% 6 Cold 5 1 As sodium hypochlorite.

Table VIII NO. 4FORMULA FOR STAIN TREATING [Standard size 42 x 84 openpocket washer] Water Temp, Time, Operation level, 1*. minutes inches (1)Flush 6-8 Hot 3 (2) Rustremovahoxalicacid conc.0.2%. 3 165 3 (3) Flush12 Hot 8 (4) Flush 12 Hot 3 (5) Alkali break: Orthosilicate cone. 0.4%,tetrasodiumpyrophosphate (TSPP) conc. 0.1% 3 195 10 (6) Flush 12 150 3(7) Flush 12 150 3 (8) Suds bleach: Soap concentration 0.1%, bleachconcentration 0.1%. 6 145 (9) Rinse 12 145 3 (10) Rinse 12 140 3 (11)Rinse (remove bleach), sodium thiosuliatc concentration 0.02%-. 12 120 5(12) Rinse 12 Cold 3 .(13) Sour, ammonium silicofluoride cone. 0.02% 6Cold 5 1 As hypochlorite.

THE PROBLEM SOLVED BY MY INVENTION The values referred to above aredependent upon the objective of the laundryman. If his objective is aminimum damage to the fabric, he will, for various types of itemslaundered, employ for the criteria of normal those conditions which givea minimum of washed laundry which needs rcwashing with a minimum amountof damage to the laundry. If his objective is to obtain minimum of itemsthat must be rewashed, he may use those conditions which produce suchminimum without regard to the damage resulting from such conditions. Ifhis objective is to minimize the damage Without regard to the number ofitems which will require rewashing, he will use those conditions whichwill give him the minimum damage and suffer the consequences of theexcessive number of items which will require rewashing.

It is to be recognized that laundering, i.e., washing procedures andbleaching procedures, are all rate processes and also statisticalprocesses. What is involved are a large number of foci of soil onfabrics, and the process of soil removal and of bleaching is aheterogeneous physico-che-mical reaction which, in the sudsingoperation, depends upon the magnitude of those foci, the concentrationof alkali and detergent, temperature, time, and the number of suchsudsing steps employed.

The bleaching operation is also a rate process and depends on thequantity and character of the soil foci remaining after the sudsingsteps, the concentration and quantity of bleaching agent, the pH of thebleaching bath, the temperature of the bleaching bath, and the durationof the bleaching step.

The quantity of soil foci and the pH of the bleaching bath are dependenton the antecedent conditions in the sudsing steps. Therefore, thelaundryman may adjust any one or more of the factors entering into thelaundry formula to reach the objective he sets for his operation,provided he knows what he is doing.

The laundry operation may be said to be eificiently operated if theproduct is produced clean with a. damage to fabric and with a mini-mumuse of chemicals at minimum temperatures and times.

The laundering operation as stated above is a rate process, and thechemical and physico-chemical reactions involved depend not only on thetimes and temperatures but also on the character of the mechanicalagitation and the ratio of chemicals to soil and to fabric present inthe various steps and concentrations and quantities of chemicals.

Thus, insuflicicnt alkalinity or insuflicient time in the sudsingoperation may result in insuflicient removal of soil, so that anexcessive amount of soil is present during the bleaching step.

An excessive alkalinity or an excessive temperature or an excessive timein the alkaline bath may cause damage to the cloth, particularly if itis alkali sensitive.

In like manner, an excessive agitation or excessive time duringagitation in the sudsing bath may cause physical damage duringthesudsing and rinsing.

An insufficient bleaching results in an excessive amount of stainedfabric that must be rewashed. This insufficiency may be caused either byinsufficient soil removal in the sudsing step or insufficient amount ofbleach in the bleaching step, or insufficient temperature, time oragitation in the bleaching step.

An excessive bleach results in damage to fabric, and this may be causedby an excessive ratio of bleach to soil, or bleach to fabric, i.e.,concentration and amount of bleach chemicals, excessive alkalinity,excessive tempcrature, and undue duration of bleaching step, andinadequate agitation.

The purpose of the souring operation is to destroy the bleaching agentwhen it is used, or the residual alkalinity when no bleaching step isused. If inadequate rinsing or souring occurs, the bleach will persistthrough ISCC-NBS numbers.

the souring step and be retained by the cloth, and may continue to actafter washing and cause damage to the cloth. This occurs when the pH ofthe sour bath is insufliciently low.

THE DETECTORS OF MY INVENTION Since the detector samples and the testprocedure depend on color and color changes in the dyed textilematerials and the inked sheet material, the following will beexplanatory of the term used in identifying the colors and dyes.

Dyes are classified by a color index, as is well known to dye chemists.This color index is entitled Colour Index, published by Society of Dyersand Colourists, Manchester, England, 2nd adition (1956). This bookidentifies the composition and characteristics of the dyes, and will beherein referred to for this purpose, and is incorporated into thisspecification by this reference.

This book classifies the various dyes by a number which is prefixed bythe symbol CI. As is shown in the above volume, dyes are classifiedunder a CI number, which number includes various dyes believed to be ofsimilar chemical constitution and which in use will give similar colorsand dye properties. It also lists a number of examples of the dyesincluded in the classification under such CI number and gives theirconstitutional formulas.

Color may be identified by employing the nomenclature of various systemsgenerally adopted for such'purposes. See I.S.C.C.N.B.S., Method ofDesignating Colors and a Dictionary of Color Names, National Bureau ofStandards Circular 553, U.S. Department of Commerce. This circulardescribes and correlates various systems by which color is designated.In this specification, where ISCC-NBS colors are designated by referenceto ISCC-NBS designations by means of numbers, it is intended to includeall colors, however designated, under the ISCC-NBS number specified.These ISCC-NBS designations by numbers will be hereinafter referred toas Since such classification 'in some cases includes two differentcolors separately designated in any color system included within theISCC-NBS numbers, and a closer designation is desired, reference will behad to both the ISCC-NBS number as well as to the designation by someother classificaiton. Thus, for example, 145 Medium Green, i.e., rnGl45(given at page 62 of the above circular) includes various differentcolors given in the Merz & Paul Dictionary of Color and four colors bythe Plochere Color System and various other colors by otherclassifications, all identified in the circular. Where, however, it isdesired to isolated such colors, as, for example, only Plochere Color1034 is specified, then this excludes all colors not equivalent to thePlochere Color 1034.

It is to be noted in this connection that Plochere Color 1034 may alsobe designated by other systems, for example, in the Munsell system itwould be designated as 6.0G3.8/ 2.5 and the Munsell system will also beused in the following descriptions. Identification of these systerns,which are standard and well known, may be had by reference to the abovecircular.

In the discussion which follows, colors will be referred to by theirPlocher-e number and corresponding Munsell Color. An article by W. E.Knowles Middleton in the Canadian Journal of Research 'F27: 1-21,January 1949, shows how it is possible to cite either or both numbers indefining color changes.

Dyes and pigments used in forming the various detectors employed informing the tester combinations of my invention have been selectedbecause f their properties in producing dyed textiles and paper andother sheet material, which undergo specific color changes indicative ofthe parameters previously discussed. While the dyes and inks specifiedherein are chosen because they have shown properties most preferable inindicating these parameters, it will be understood that other dyes andinks having sim- Dyeing procedures are shown below. Wherever percent isused, it means ratio of the weight of the paste or concentrate used tothe pounds of fabric dyed.

Table IX Percentages by weight of dye in the dye bath used was asfollows:

Dyes classified in colour index as dye color Detector #1, Bleach green.01 59,850 5% of paste. Detector #2, Light blue CI 7 6% of paste.Detector #3, Dark blue- OI 73,065 8% of double paste. Detector #4, PinkCI 16,605 1.25% of paste. Detector #6, W001 dye CI 45,100 2.0% of paste.Detector #7, Direct green (Seal below) These pastes are the commercialdesignations of the dye concentrations used.

The regular reduced jig method was used on the first four dyes shownabove. Essentially it was as follows:

Bleached x 80 print cloth was used; hence, preliminary scouring wasunnecessary.

The liquor ratio was six to one (6:1). The pastes were reduced with asolution of concentration of 0.02% caustic soda and 0.025% sodiumhydrosulfite. The reduced dyestuif was introduced into a bath thatcontained a concentration of 2% caustic soda and 2.4% hydrosulfite. Thefabrics were run in the dyebath for /2 hour at 140 F. The cloth wasremoved and the cloth rinsed in cold water until the dyes were oxidized.

The fabric dyed CI 16,605 of detector No. 4 was given additional rinsingbecause it is not treated by the usual soaping off treatment. The otherthree vat colors were soaped off with 1% perborate and a neutral soap,

starting at and going to a boil. All of the fabrics were dried on atenter frame.

An acid dyeing was used on the wool fabric of detector No. 6, using CI45,100. The liquor ratio was 40:1. The dyeing was carried out in asolution of a 20% anhydrous sodium sulfate bath with 4% concentratedsulfuric acid (35 Baum). The starting temperature was One half hour wasused to reach a boil. The fabric remained at this temperature for onehour. Normal rinsing procedures were used. No after treatments weregiven.

The wool fabric itself is a white worsted flannel, style 503-A, that issold by Testfabrics, Inc., 55 Van Dam Street, New York 13, New York.

The dyeing procedure for the green fabric, detector No. 7, dyed with thedyes as described below, was that common for dyeing with direct cottondyes. The standard 80 x 80 print cloth was cut and hemmed into 72 inchlengths in order to avoid tangling in a commercial washer. The size ofthe machine was 36" in diameter and 54" long. Its rotational speed was21 r.p.m., reversing after each 7 /2 revolutions. The liquor ratio was30:1; NaCl was used, based on fabric weight. Cross comparisons with labdyeing gave identical performance to those dyed in the commercial washeron all types of washing formulas, except extremely mild procedures usedby the average housewife.

The dye transfer from this fabric to the sack that surrounds it, as ismore fully described below, during the average washing formula, can becorrelated with the dyeing characteristics of this dyestulf; i.e.,regardless of time, temperature and salt content, complete exhaustion ofthis dyestuif is impossible. Also, only one-fifth of the color goes onto the fabric at 120 F, compared'to 9 an identical concentration at 160or 190. Hence, by starting the dye bath at low temperature and thenraising it with steam, we .achieved uniform dyeing not only from batchto batch, but also over every square inch of fabric.

The concentration of the dye in the dye baths employed is such as toavoid either extremely high concentrations or such low concentrationssuch that pastel shades are produced.

The following examples of the dye concentration on the fabric dyed withCI 59,850 are given by way of illustration and not as a limitation of myinvention.

Where the dye bath is made up with 10% instead of of paste, thisproduced a fabric that turned black with mild bleaching intensities, andit was difficult to differentiate between mild and normal intensities.

The 5% concentration given above was selected as the optimum inevaluating changes in ordinary light.

Concentrations ranging from 2.5% down to 0.1%, graduated as follows:2.0%, 1.0%, 0.5%, 0.25% and 0.1%, showed a tendency to lose sensitivityto bleaching intensity when viewed in ordinary light. At a concentrationof 0.1% it was necessary to use an ultraviolet light to observe thedifference between medium and heavy soil formulas.

The Plochere and Munsell colors of these dyeings ranged as follows:

The effect of dye concentration of the fabric for detector No. 2 was asfollows: 6.0% paste yielded the color changes shown previously, and a2.0% of paste in dyeing gave a tester which became colorless at low pHvalues instead of yielding a yellow color, as desired, and as will bedescribed below.

Three concentrations were tested with the Dark Blue, CI 73,065, detectorNo. '3. A solution made up with by weight of double paste produced afabric which was insensitive to changes in bleaching intensities commonto fairly severe heavy so-il formulas. A 6.0% solution, on the otherhand, gave color changes that were about the same as those of detector#2. Either of these concentrations could be used. However, the fabricdyed with a dye solution containing 8% by weight of the double paste wasselected a the most satisfactory.

When using CI 16,605 dye for detector No. 4, a solution containing 2.5%by weight of the paste did not show the characteristic change to a blueshade, as is described below, as readily as 1.25% when the dyed fabricis viewed in ordinary light.

The reddish purple woolen fabric of detector No. 6 was dyed with 1.0%and 3.0% by weight of the dye paste employing dye CI 45,100. Sincealmost any commercial laundry formula decolorize this fabric, a 2.0%dyeing was adopted as standard. In testing extremely mild formulas, afabric dyed with a solution containing 1% by weight of paste would beadvantageous.

In forming detector No. 7, a dye solution containing 1.0% by weight ofthe following dye mixture was completely decolorized by the severe stainremoval formula in which both bleaching and alkaline intensities arefairly high. A solution containing 2% by weight of the dye mixtureretained enough color to differentiate between heavy soil formulas andthose used for stain treatments; hence, it is preferred.

The dye mixture was as follows:

97.20% by weight of CI No. 30,925

2.50% by weight of CI No. 11,020 .05% by weight of CI No. 19,555

In every case the detector, after dyeing, should be air dried, carebeing taken that it is not heated or ironed after air drying, orexcessively tumbled during drying.

For convenience, the detectors 4 to 8 are mounted on a large swatch,edges pinked, of poplin, forming detector 8a. Detectors 1 to 3 may beseparately mounted on a piece of fabric or mounted together with 4 to 7on detector 8a.

FIG. 1 illustrates a tester formed of detectors 1 to 8 mounted ondetector 8a.

FIG. 2 is a section taken on line 2-2 of FIG. 1.

FIG. 3 illustrates another tester, to be employed where no bleachingstep is employed, and showing the detectors 4 to 8 mounted on detector8a.

FIG. 4 is a modification of the tester of FIG. 1.

In following portions specific examples of the changes in the detectorsare explained. For best results it is desirable to preserve a separate,unused set of detectors and compare the detectors after test with thefresh, unused detectors.

Detector N0. ].-Detector No. 1 is a bleaching intensity indicator,composed of a textile such as a swatch of cotton fabric or a piece ofcotton yarn dyed with a dye which changes in color if the bleachingintensity is moderate or excessive. A preferred form is green fabric, asdescribed above, which was dyed by the above procedure with 5%concentration of No. CI 59,850 dye (CI Vat Green 9believed to bedinitroviolanthrene), to give a color equivalent to ISCCNBS No. 145, andprefer-ably a color equivalent to Plochere 1034 or Munsel 6.0G 3.8/2.5.

This green fabric is pinked at the edges and identified as 1, located onthe left side of the first (top) row of FIG. 1, mounted in detector Soby stitching it to the fabric of detector 8a by a line of stitching In.It will turn black with a concentration of bleach based on liquor volumeof 0.01%; and in the presence of normal quantities of soil in theaverage commercial laundering. More soil or less bleach will cause it tochange to darker shades of green, e.g., Plochere 1089-Munsell 2.5G2.3/0.8, or Plochere 1049-Munsell 4.0BG 25/05. The change is unaffectedby the pH of the bleach bath. Neither chlorine in the water supply orfrom soiled towels. as employed in commercial laundries is ofsufliciently high concentrations to cause the fabric to turn black.Chlorine con centrations of 0.1% do not intensify the black color. 1 Itmay lighten the color, due to the intensity of the bleaching eifect. Itbecomes evident that additional fabrics are required to measure severebleaching effects.

There are no color changes in detector #1 which in dicate undesirablebleaching conditions. The objective of every commercial laundry is toachieve stain removal with the minimum bleaching intensity. Ifsatisfactory stain removal can be achieved without causing a change toblack, the operator of the laundry would be quite content. If, on theother hand, appreciable quantities of his towels and garments wouldrequire a rewash or stain treatment, it would be desirable to purposelyalter the formula so as to increase bleaching intensity which would bereflected in a blackening of this detector.

Detector No. 2.-Detector No. 2 is an alkali reaction intensityindicator, composed of a textile such as a swatch of cotton fabric or apiece of cotton yarn .dyed with a dye which changes in color and losescolor as the alkalinity of the bleaching bath increases, or the time inthe bleach bath increases, or the temperature increases, or theconcentration of bleach is increased. It may, for such reason, he saidto be an indicator of the product of the effects of alkalinity, time ofbleach, temperature of bleach, and bleach chemical concentration. Thepreferred form is the light blue fabric, as described above, which wasdyed by the above procedures with concentration of dye No. CI 74,140 (CIVat Blue 29-partly sulfonated cobalt phthalocyanine), to give a colorequivalent to 11 ISCCNBS No. 169, and preferably a color Plochere 771 orMunsell 6.0B 4.9/9.0.

This light blue fabric, pinked at the edges, is identitied in FIG. 1 as2 and mounted on the fabric of 8a equivalent to 12 is responsive tototal bleaching intensity becomes apparent. This is achieved by usingthe dark blue fabric CI 173,065, detector 3.

Detector N 0. 3.-Detector No. 3 is a bleaching intensity by a line ofstitching 2a. The fabric will lose color as 5 level indicator composedof a textile such as a swatch of the bleaching intensity increases. Ifthe pH of the bleach cotton fabric or a piece of cotton yarn dyed with adye bath stays above 10.2, a blue shade will result, even which losescolor without substantial color change if the though appreciable colorloss occurs. If, however, the bleaching intensity is excessive. It is anindicator of the pH drops to 9.2, the resultant color will be green, andminimum level of bleach concentration and also indiwith a pH value of8.2, a yellow color will be observed. cates the level and temperature ofbleach. It may, there- During the average bleach bath in a commercial orfore, be said to be an indicator of the minimum level household washerthe color loss is proportional to the of the product of the effects ofbleach concentration, time rate at which the bleach is decomposed.Generally, sufand temperature, to indicate the existence of a bleachingficient alkali is present to maintain a blue shade. If the t, and l alsoindicate a level of bleach intensity pH. of the bleach bath isdeliberately lowered to 6.5, greater than the desired level ofbleaching. It is subby the use of la polyphosphate, the light bluefabric will stantially insensitive to alkaline pH, and thus willindichange to a tan color almost instantly, and then the shade cate anexcessive degree of bleach resulting from either changes fro yellow toalmost white will occur if nffitoo large a concentration of bleachchemical or too high cient bleach is present. Neutral pH bleaching bathata temperature or excessive time. It thus is a measure tacks theamorphous region of cotton fibres, and thereby 0f t n d effect f bleachCOIlCeIltratiOIl, mperarenders them sensitive to subsequent alkalinetreatments. ture and time 011 the intensity of bleach attained. Colorchanges in this light blue fabri thu erve two A preferred form is thedark blue fabric, as described purposes-avoiding too much bleach, andavoiding bleachabove, a y y the above procedure with concentration ingat neutral pH values on regular wash loads. of CI No. 73,065 dye (CI VatBlue 5; for its constitutional The dyestulf in this fabric is mildlychlorine retenformula, see the Colour Index), to give acolor equivalenttive, if the bleaching intensity is severe; and, in additon, to ISCC-NBSNo. 194, and preferably a color equivalent evaluation of the detector isdelayed for several days to Plochere 625 or Munsell 8.0PB 2.8/14. or 'aweek, on regular loads, there would be a shift in The dark blue fabric,identified in FIG. 1 as 3, is hue from blue to green. On stained loads(where appinked at the edges and mounted on the fabric of detecpreciablequantities of bleach are required, i.e., 0.1% by tor 3a by a line ofstitching 3a. It does not lose a noweight), the shift in hue will befrom green to tan; and ticeable amount of color when subjected to theaverage at higher bleaCh concentrations "ihfire W111 commercial orhousehold laundering. When it is necesbe a complfite 1055 of 1010f WanotlPeable weakening sary to re-wash fabrics in order to removestubborn of the fabnc' In Prdsr to avold shlfi I f an stains, such asmildew, a moderate loss of color occurs. 32 X sggfig gg i i fl gg 3; gggg n ti 35 In this case pH values do not alter the final shade change.der a fraction of 1% the rinse i g if; (in rewash loads in a commerciallaundry, where the quan- 0 0057 t 0 057 f 1 r a p tlty of oxidizablesoil is at a minimum, an initial cono o a or examp e, 0.01% is suitable.t f 017 M h t 0 F f 20 t The desirable and undesirable changes in colorin this ra lon o 1 0 eac a or i es Will cause sufficient color loss tobe readily recognizable. fabric depend on the specific ObJCCtlVC of thewashing 40 F formula. For example, bloody stains on butcher aprons or mi einploymg Formula 2 4 Wlth a hqind are best removed with a high pHbleach bath. In this to fabnc who ol at the 18 coPsecutlve Case, theblue color of this detector may decrease in removal treatments a littlecolor w1ll still remain in the tensity, but it does not shift towardsgreen or yellow fabric; Tables XI XIL) h Haw/aver, h mildew stains, thePH of the bleach 425 This fabric is quite useful in relating therelative inb th must b l d, M h l bl h i required at tensity of onestain removal treatment to repetitive norpH val e may 7,0 th t 9,() Th agreen color with mal launderings. In some commercial laundries therathis detector would be desirable, provided that excessive tio is 2031;that it Tfiquires twenty Consecutive regular quantities of bleach wereavoided. The need fo a f blaunderings to induce a loss in color thatmatches that ric that is not affected appreciably by pH values and ofone stain removal treatment.

Table XI EXAMPLES OF COLOR CHANGES WHICH OCCUR WITH BLEACHINGINTENSITIES WHICH MAY BE ENCOUNTERED IN COMMERCIAL LAUNDRIES Detector No. 1 Detector N0. 2 Detector No. 3

Plochere Munsell Plochere Munsell Plocherc Munsell a aggre atin2a..-ei833 2:283:2/315 a as are as at: (3) haillerglzgdglelaigiing,maximum change 1049 4BG 2.5/0.5 772 7B 5.7/9 625 8.0PB 2.8/14 (4)Fzifiglggntiegrileablgagfing, maximum Black 773 7.5B 6.5/8.5 626 8.0PB3.8/13 (5) Segeg rg e a cgl ng r i a x i r l l1 m change Black 774 8.0B7.6/7 627 8.0PB 5.6/13 (6) Dls gitggeebggzlilaigibtglgrrizgangeindicates Black 776 9.0B 9/3 628 7.5PB 6.4/12

Slightly alkaline bleach Neutral bleach Plochere Munsell PlochereMunsell (7) My); gliillidllgaggfigfelrgggglnum changes Black 1030 6.5G8.0/3.5 38 5.5Y 8.5/2.5 026 8.0PB 3.8/13

13 The following illustrates the changes in color of the detectors undervarious bleaching conditions:

Table XII Plochere Munsell Detector #1 (Bleach sensitive green):

Control 1034 6.06 3.8/2.5 Mild bleach.-- 1039 2.5G 2.3/0.8 Severe bleach1049 4136 2.5/0.5 Black (excessive bleach) None None Detector #2 (bleachsen itive light blue):

Ontrol.. 771 6.013 4.9/9 Mild bleach. 772 7.013 5.7/9 Normal bleach 7737.5B 6.8/8.5 Severe bleach 774 6.013 7.6/7 Green (slightly alkalinebleach) 1030 6.5-G 8.0/3.5 Yellow (neutral bleach) 38 5.5Y 8.5/2.5Detector #3 (bleach sensitive dark blue):

ontrol 625 8.0PB 2.8/14 Mild bleach. 626 8.0PB 3.8/13 Normal blea 6277.5PB 6.4/12 Severe bleach. 628 7.0113 7.5/

Table XIII Plochere Munsell Original color 625 8. OPB 2.8/14 Heavy soilbleaching- 626 8. OPB 3.8/13 Stained load bleachin 627 7. 51 B 6.4/12Excessive bleaching. 628 7. OPB 7.5/10

Reference should also be made to Table XII in this connection.

In the Plochere system a change in number from 625 to 628 indicates theaddition of increasing amounts of white pigment to the original color.With the Munsell system, hue segment of purple blue is described by thefirst digit. A change from 8.0 to 7.0 is very small. This explains thedifference for the Munsell number for the Plochere 6 27 and 628 of TableXIII, as compared with Table XII. The accuracy of the observation thatthis dye is unaffected by pH values of the bleach bath is furthersubstantiated by the fact that the range of values in the second portionof the Munsell system is regular and normal, i.e., 2.8 to 7.5. Thisnumber describes the grayness of the color change. That is, a value of0.0 is black, 5.0 is gray, and 10.0- is white. The regularity of thegroup ing in Table XII about 5.0 is apparent. The last number under theslash describes the intensity of the hue, often referred to as chroma orsaturation. These numbers range from fractional 0.5 to 20. This makes itpossible to be quite explicit in stating desirable and undesirable colorlosses. Hence, if the change in color for a medium soil formula (seeTable X1) is as great as that shown for a heavy soil formula, correctivemeasures should be initiated. The conditions shown for Plochere No. 6 28(Tables XI and X11) are highly undesirable for anyregular washingformula, and should be avoided even for stain removal treatments.

These three detectors 1, 2 and 3, when used together in the bleachingstep, will indicate whether the bleaching is insufficient, or normal, orexcessive. Detector No. 2 Will also indicate whether the pH was eithertoo high, normal, or too low.

If these three indicate insufficient or excessive bleaching, it willnot, if the improper conditions arise from other than abnormal pH,reveal this abnormality in the other parameters.

This abnormality is indicated by detectors 4, 5, 6, 7, 8 and 8a,described below.

Detector N0. 4.--Detector No. 4 is a temperature indicator composed of aswatch of cotton cloth or a piece of cotton yarn dyed with a dye whichis temperature sensitive, and will indicate whether the temperature isbelow a determined temperature set as normal for this operation or isabove such temperature. It may thus be termed a temperature levelindicator. This textile is enclosed in a plastic film formed of apolyamid of a dibasic acid, sold as Nylon Autoclavable film by theSierra Manufacturing Co., at Sierra Madre, California, and heat sealedto make it impervious to dyes or optical brighteners used in the washingprocess, although not impervious to water. This sealed package isenclosed in a heavy, unbleached cotton sheathing, to protect the plasticpackage against mechanical damage. It may be used alone, as shown inFIG. 4, or together with detector No. 5, as shown in FIGS. 1 and 3.

A preferred form is the pink fabric, as described above, dyed by theabove procedure with concentration of dye CI No. 16,605 (CI Acid Red orPink PR l24f0r its constitutional formula, see the Colour Index), togive color equivalent to lSCC-NBS No. 248, and preferably a colorequivalent to Plochere 388 or Munsell 8.0RP 5 .5 11.5.

The pink fabric is identified on FIGS. 1 and 2 as 4 and is enclosed in aheat-sealed plastic envelope 14 and enclosed in an overfolded muslincloth formed into an envelope by lines of stitching 11 and mounted onthe fabric of detector 8:: by a line of stitching 12. This fabric isused to evaluate temperature effects. The original fluorescent pinkshade is achieved by avoiding the normal high temperature soaping off,i.e., washing with soap, as is described above. However, a fairly hightemperature F.) wash must be used to observe shade differentials withthe naked eye. Observation in a darkened room with the use of anultraviolet light makes it possible to differentiate twenty degreetemperature effects, provided, of course, that the time factor is heldconstant.

Because the detector is enclosed in the plastic envelope, opticalbrighteners employed in detergents or laundry sour do not aifect theseeffects. However, if not enclosed in the envelope, the action of opticalbrighteners can be overcome by the following procedures.

Optical brighteners are dye stuff which are substitutes for blueing,generally used in household detergents. Two methods can be used toovercome this ditficulty:

(1) Use an ultraviolet light source, such as a mercury arc light inquartz, Whose radiation peaks in the vicinity of 2537 Angstrom units,instead of the conventional ultra violet light, whose peak radiation isin the vicinity of 3 600 Angstrom units.

(2) Use an orange filter. This orange filter, sold by the NationalMarking Machine Company, is for reading fluorescent laundry marks. Asimiliar Wratten optical filter No. G may be employed.

This detector No. 4 aids appreciably in evaluating detergent efliciency.Thermostat failures have been detected on automatic washing equipmentwith the use of this tester. Most commercial laundries use washingformulas that are approximately one hour in duration. An average of tensudsing or rinsing operations is used. This tester measures combinedtime and temperature effects; hence,

the maximum temperature that has been attained during asuds bath of awashing formula cannot be determined unless the time and temperature ofother steps such as the rinses have been held constant.

Detector No. 4 is not affected by soap, alkali, detergent, bleach, orlaundry sour when applied cold. Suitable precautions must be observed inavoiding pressing the fabric when it is wet. The heat of a laundry press(315 F.) will distort washing temperature effects.

The changes in color with detector No. 4 are independent of bleachconcentration orconcentrations of alkaline detergent, and are dependentonly on temperature and time.

Temperatures of or more in excess of those specified in Formula 2, forthe period of the formula, will cause a perceptible darkening of thevisual shade of detector No. 4 or, under ultraviolet light, a decidedloss in fluorescence. It is therefore desirable to establish a standard,by careful control of the washing cycle temperatures using a test swatchof detector No. 4, and use this as a standard of comparison withdetector No. 4 in washing procedures in which this detector is employed.

It will make little difference, even if the detector is not enclosed inthe envelope, whether subsequent washes em ploy brighteners differentfrom those used in making the above standard run, since the comparisonis in the same narrow range of the spectrum.

For identical temperature conditions, samples employed in baths with andwithout brighteners, when viewed under ultraviolet light and with afilter, show the same fluorescence intensity.

This fabric gradually develops a bluish cast at high temperatures. Lowtemperature washing (about 145) can be observed in ordinary light. Anultraviolet light is needed to detect 20 F. differentials when fairlyhigh (180) temperatures are used. An orange filter, along with theultraviolet light, is desirable to observe 20 F. differences whenoptical brighteners with a bluish cast have been added to the washingsupplies. Brightener may also be transferred from soiled towels to thetester as the load is being washed. Restaurants often rinse out rentedtowels in household detergents that usually contain appreciable amountsof whitening agents.

Color changes with detector No. 4 under various conditions are given inTable XIV below.

Table XIV COLOR CHANGES WHICH OCCUR WITH THE PINK FABRIC (DETECTOR NO.4)

The Plochere colors of detector No. 4 which can be seen with anultraviolet light are shown below.

Comparison of these colors with actual washed swatches in a dark roomwould be difficult. It is suggested that separate detectors No. 4 bedeliberately washed at low temperatures and at very high temperatures,and these can then be used to monitor detector No. 4 when employed intesting laundry operations.

Reasonable precautions are needed to avoid the crroneous assumption thathigh washing temperatures may have been used. When colored industrialfabrics are laundered, enough dye may be redeposited on this fabric todarken it, thereby giving abnormally high temperature effects. Thewhiteness of the backing, i.e., detector No. 8a, for these swatches,shows whether or not this has happened. The backing will also show ifappreciable quantities of fluorescent brightener were present in thesoiled load or the washing supplies. Brighteners with a blue cast underan ultraviolet lamp also give abnormally high temperature efliects,unless an orange filter is used.

Detector N0. 5 .Detector No. 5 is a temperature indicater composed of apiece of paper carrying a temperature-sensitive chemical which changesin color, and which color change is visible to the naked eye underordinary daylight. This color change is dependent upon the time andtemperature to which it is exposed and will indicate the effect of suchexposure during a period of time at varying temperatures, or of varyingdurations of exposure at a fixed temperature. It may thus be termed atimetemperature indicator. It is chosen to give a change which will bedetectably different if the temperature is abnormally low, normal orabnormally high for the duration of the laundry process during which thedetector is employed.

A preferred detector is a paper impregnated with paint formed of boiled,i.e., an oxidized, linseed oil, mixed with a petroleum thinner, carryingas a pigment a mixture of anhydrous chromium chloride and also titaniumoxide as a brightener. The paper is immersed in the paint and then airdried at an elevated temperature to remove the thinner. The chromiumchloride, in its anhydrous form, is purple in color; and on exposure tosteam or moisture, it picks up six molecules of water, but is stillpurple. On exposure to an elevated temperature in the laundry process,as described below, its color changes from purple to blue to gray and togreen. This change is progressive and is a function of time andtemperature, as will be more fully described below.

The paper may be enclosed in a plastic film, as in the case of detectorNo. 4.

Instead of using the above paper, we may use detector No. 4 as above,which also then acts in place of detector No. 5, and view the colorchange with 'an ultraviolet light. The fluorescence intensity is ameasure of the time-temperature effect described above.

The detector is identified as 5 in FIGS. 1 and 2, and is in the sealedplastic envelope 113 and enclosed in the muslin envelope 14.

Table XV Shade change in ordi- Oolumn A Column B Column 0 Appearance ofsame Same fabrics that were nary light fabric in darkened roomdeliberately treated with with an ultraviolet light an opticalbrightener Row No. 1, unwashed detector: A treatment wigh a codliriglliitener Plochere 388 Plochere 289 Ploehere 349.

solution would not chan e its appearance in or inary ay ig Row N0. 2:One washing with a formula No. 1 in the F. range. Munsell 7.5RP5.0/8.0... Munsell 5.0R 4.0/0.0..- Plochere 357.

The chau "e in ordinary daylight is not very pronounce Row No. 3z Onewashing with a formula No. 3 in the range. The Plochere 443 Ploehere 386Ploehore 341.

bluish cast begins to develop.

Row No. 4; Washing temperatures in 200 range (excessive heat) Plochere451 Ilochere 433 Ploehere 397.

1 7 Table XVI COLOR CHANGES IN DETECTOR UNDER VARIOUS OPERATINGCONDITIONS Merz and Paul colors (1) Color of original detector Plate41-F-5. (2) Abnormally lowtemperatures for all treatments Plate 42-D-5.

except light soil formulas; for example, Formula Detector No.6.--Detector No. 6 is an alkali-reaction intensity indicator composed ofa textile such as a swatch of wool fabric or Wool yarn dyed with dye CINo. 45,100, which loses color without substantial color change anddisintegrates progressively with increases in alkalinity for givenperiods of time. The degree of disintegration is a function ofalkalinity and time. This indicator may thus be termed analkalinity-time indicator. The fabric or yarn is enclosed in a piece ofpoplin. This poplin may, if desired, be treated to have achlorine-sensitive finish. The above is more fully described below.

The reddish purple wool fabric, as described above, was dyed with aconcentration of dye CI 45,100 [Wool Dye Red 748 or Acid Red No. 52(Rhodamine B)-for constitutional formula see Colour Index], to give acolor equivalent to ISCC-NBS No. 254, and preferably color equivalent toPlochere 43-4 or Munsell 7.5RP 3.9/13.

This fabric is made from a wool-like material which is unaffected bymost bleaches, soaps or detergents, as well as hot soft water. Thefabric is enclosed in fabric which is overfolded and formed into anenvelope 15 by stitching 16 and connected to the fabric of 8a by a lineof stitching 17, to protect it against mechanical action of theagitation and to retain the fabric even if it is disintegrated. It willwithstand a brief cold soak in a washroom concentration (0.25% byweight) of a fairly strong alkali (orthosilicate). Higher concentrationsor stronger alkalines first destroy the color and then destroy'thefabricitself. Its-small size reduces mechanical damage during theaverage washing formula. The small sack protects it from completedisintegration during the last part of heavy soil formulas or whenalkali concentrations are fairly high.

Both time and temperature contribute to damage caused by alkali. Theyshould remain constant if two different alkalies are compared. Onlyapproximate pH values are shown below, because they are usuallyreducedduring the average break or sudsing operation, due to thepresence of fatty soil. It should not be assumed that these pH valuesare the only desirable ranges for linen supply washing.

A mild alkali wash, suitable for woolens, does not destroy either thefabric or the ,dyestuif. The light soil washing, FormulaNo. 1, usuallydestroys the color,.but the fabric structure remains intact. A similarsituation exists for the mediumsoil Formula No. 2. Most heavy soilformulas induce a partial disintegration of the woolen fabric itself. Ina manner analogous to that of bleach baths, time, temperature andconcentration affect the final appearance of the test fabric.

The degree of disintegration will be partiallyrelated to the rate atwhich the pH of the suds bath is lowered due to natural soil found inthe fabrics being washed. Examination of the Formulas No. 1, No. 2, andNo. 3 will show that the temperature of the Wash load must be raised byadmitting live steam to the washer at operation step No. 2. Obviously,both the rate at which the temperature is raised and the rate at whichalkalinity is lowered will affect the appearance of this fabric.

A concentration of 0.38% tetrasodiumpyrophosphate (SPP) and pure soapdoes not alter this fabric during a light soil formula, similar toFormula No. 3. A slight color loss occurs since pH values range from10.2 to 9.8, using the standard glass electrode on an electric pH meter.A concentration of 0.13% of ordinary liquid hypochlorite bleach will notdestroy either the color or fabric during an 8 minute exposure at F.,when the pH values range from 9.8 to 8.3 during the bleaching bath.

The presence or absence of soap does not alter the end resultsignificantly. A few nonionic detergents affect wool adversely, but theyare not used extensively. On industrial washing classifications, such asshop towels or coveralls, there is a tendency for soil to collect onthis woolen fabric Whenever the soil suspending power of the washingbathis lowered significantly.

Visual examination of this fabric does not permit decideddifferentiation between medium soil and light soil washing formulas. Thegreen fabric in the large sack, described in detector No. 7, suppliesthe necessary information in this range of detergency.

The Pl0chere and Munsell color changes which occur as the reddish purplewool fabric of detector No. 6 loses color are shown in the followingTable XVH.

Table XVII Row Ploohere Munsell 1 Original color 434 7.5RP 3.9 13 2, Medum soil washing without 437 2.5RP 6.2/12

alkali. pH range 9.8. 3 Medium soil washing with trl 440 5.0RP 9/8sodium pyrophosphate and soap, pH range 10.2. 4 Normal light and mediumsoil Color gone but fabric is unformulas. altered. 5. Mild heavy soilformula Color gone, fabric is felted and has started to disintegrate. 6Fairly severe heavy soil formula. 0231(1): gone, also most of the a no.7 .Stain treat formulas with high Last traces of the fabric arealkalinity. gone; only the empty sack remains.

In the above Table XVII, the following explanations apply to items 1-7:

(1) Color of the original unwashed fabric. The cloth is soft andresilient.

(2) This indicates an example of the change with a low pH wash--about9.5. This color produced resulted from employing a medium soil formulawith the alkali purposely omitted.

(3) This color change is an example of a light soil formula employing pHabout 10.0. The color was destroyed but the fabric is intact.

, (4) This change is an example of the use of an average medium soilformula, where the pH value is about 10.8 to 11.0. The color wasdestroyedybut the fabric is intact.

(5) This change resulted fromthe use of a mild heavy soil formula, withpH values of 11 .5 to 11.8. Many kitchen soil formulas partially destroythis fabric.

(6) This change is the. result of .a fairly severe heavy soil formula,with pH values in the 11.8 to 12.3 range.

19 Most of the fabric has been dissolved and washed away. (7) Thischange resulted from a formula employing excessive alkalinity with pHvalues in the 12.4 to 13.0

. 2i) The preferred form is a-green fabric, dyed with a concentration ofdyes specified below, to give a color equivalent to I'SCC-NBS No. 151,and preferably color range. It completely destroyed both color andfabric. equivalent to Plochere 977 or Munsell 2.5BG 2.7/2.0; Only theempty sack remained. 5 The dyes are identified by Colour Index asfollows: CI Industrial garment loads often contain, appreciable 30,295(CI 7 Direct Green or C.B.M. No. 593); CI amounts of oil and soil. This,along with loosened dye 11,020 (Oil Yellow B.B.); Cl. 19,555 (YellowB.W.P.). from colored garments, may redeposit on the fabric in- For theconstitutional formulas of the above dyes, see the side this sack. Insome cases this condition may lead to 10 "Colour Index. gray work ordull colors. Color loss of this direct cotton dyestuif has been found Ithas been observed that chlorine retentive finishes to correlate with thestain removal efficiency of washing that are applied to wash and wearcottons will retain formulas used for rental linens supplied bycommercial very small quantities of bleach in the average washinglaundries. A gradual increase in color loss can be obformulas. Theretention of the bleach on the washed Ser ed in F mula N0, 1 through 4,dye is tered fabric will cause attack, if the fabric is cotton, and mayb bl h so h an evaluation f detergent efliciency calls? fol-ting must bebased on pigment loss rather than shade change. Wlth lesser Flmoums ofbleach excesslve Pres This handicap does not prevent the fabric fromprovident, the effective concentration of bleach present may ingindicamion of detergent ffi i of formulas used often -be n the range of(1.005% or less. A speclfic tolaundel. salmnfirlable or fatty sol fa.bnR1ege1 s Shlp Ahoy poplin style made by As an aid to evaluate the degreeof pigment loss, deglegel Texu'le Company 8 Gland cential tector No. 7may be viewed visually by placing an untation, New York, New York, ischlorine retentive W h d f h d t t 7 l 1 f th d d t t enough to give apositive test with orthotoluidine when as ms 6 as M a ong 1 e 0 6 I itis dropped on to the fabric. The col 0 T-chan gfi is from on a lighttable composed of a frosted glass, illummated colorless to yellow toorange to red on the underneath side by fluorescent lamps. The de Thestain removal formula shown in exhibit No. 2 gree of pigmem loss 15Teadfly Observed Formula N0. 4 an operation involving the USE Industrialgarments, such as coveralls or shop towels, of an .anti-c'hlor (usuallysodium hydrosulfite). Riegel contain mineral oil that is best removed byemulsifica poplin is so chlorine retentive that it requires appreciableti011 Father than sapollification- This test fabric is of quantities ofsodium hydrosulfite to remove the last traces Value ill determining theq y of removal Of y of bleach. Hence, in this case, the sack used forhold- Stains, especially SW62"; stains, in the laundry P ing the woolfabric of detector No. 6, when made of cedure in which the detector isemployed. such fabric,'becomes a monitor against inadvertent over-Perhaps the most important use for this fabric is that use ofantichlors, which would destroy colors often found of a check or summaryof the intensity of all other fac- 1n emblems and embmidefed name's thatare used 011 tors which contribute to good detergency in launderingTental 'garments- The T@5111 0Il llhiS fabTiQ is P y fabrics thatcontain restaurant or kitchen soil. If the urea'formaldehyde- TheAmencan Dyestllfl Reporter: sudsing bath on a washing formula has beendeficient 3 ,1950, dFsonbes chlorine and the bleach bath severe, thisfabric Will change from ietenmve By usmg F fabilc for the l 40 green tobrown or tan. If, on the other hand, the suds ope 15, the orthotoluenetest, if applled to the fabnc, bath h be v d h t d alkald will indicatethat there is residual bleach in the washed b en ery Severe U6 9 an1*31} fabric. leaching effects are extremely mild, a green shade W111Detector No. 7.Detector N0. 7 is an alkali-reaction Perslst even moilghaplireclable (501m loss Ocwrs' intensity indicator composed of 'atextile such as a swatch The: loss pigment is proportional to the Stamof cotton fabric or a piece of cotton yarn dyed with a l i to bleachBieachmg without dye or combination of dyes which changes in color andPnor washmg changas amficlal SO11 from gpefln to loses color due to thecombined effect of alkalinity, tembrown as can be Seen m the TOW, ofTable perature and time. It thus measures the extent of the XV 1Hbelowone Washing will not remove all the alkali attack. This indicatormay thus be termed an green Soil: as can be seen in Column A Table Lalkalinity-time-temperature indicator, since it measures The ninePositions are desirable 1501' t linen the products of the effects ofalkalinity, time and tempp P perature. The preferred dye is more fullydescribed The fabric forming detector No. 7 is enclosed in a below.cloth envelope 18 and stitched to the detector 8a.

Table XVIII STAIN REMOVAL DETECTOR NO. 7 (Kitchen Soil) Column A B C D EColors most often observed when- No bleach is used Bleaching is veryBleaching is moderate Bleaching is fairly Bleaching is severe mildintense or excessive I II I II I II I II I II 1) With t lk ztii E2) waith? mmmrangia::::: i553? 213331323? 1333 1138313113 332 2338?? 31313133% fli ht? i3? ii iiiiiiii 3 W th moderate alkalinity..- 1036 6.585.7/2.7 1092 0.8G 5.8/2.0 1245 4.0GY 6.2/2.0 93 5.0Y 7.2/2.7 134 1.0Y8.0/3.6 4 Fairlymtense alkalm1ty 1037 7.0G 6.6/3.0 1093 0.5G 0.9/1.51246 3.0GY 7.0/1.6 94 5.0Y 8.3/1.5 135 1.0Y 8.8/3.6 (5) 1 Severe orexcessive alkalinity" 1094 10.0GY 7.6/1.0 1247 2.0GY 8.1/1.2 95 5Y 9/1'136 1.0Y 9/3 88 3Y 9/1 1 This color is so close to white that it isdifficult to designate it in the Munsell system.

Detectors 6 and 7 thus will report whether the tornperature is excessiveor whether either alkali concentration or the time of treatment wasexcessive.

Detector 8 (white Indian head fabric) and detector 8a (poplinfabric).-Detector No. 8 is a mechanical action indicator composed of atextile such as a piece of white cotton sheeting pinked :at the edgeswhich'is easily frayed by mechanical action, such as agitation andtreating in the washer.

Detector Nos 8a is a mechanicallaction indicator com,- posed of atextile such as apiece of white poplin cloth, pinked at the edges, whichis difficult to fray.

Thus, if detectors 8 and 8a are both frayed, either the agitation isexcessive or was continued for too long a time. If 8 is frayed but not8a, the agitation is excessive but the time of treatment is not tooexcessive. If neither isfrayed, both time and agitation areinsuflicient.

Since the mechanical agitation can be controlled so that, for normaloperations requiring desirable periods of treatment, detector 8 isfrayed lbut 8a is not frayed, the degree of fraying of 8 and 8aindicates the duration of the period of agitation. Detectors 8 and 8acan thus be termed agitation-time indicators.

It has been found desirable to attach detector 8 to the left side of thepoplin fa'b-ric 8a which is used to hold the various detector fabrics.This makes it possible to compare pinked edges that are comparable inlength (i.e., 8 and 8a) and observe excessive mechanicalpoundmg.

It has been observed that a pinked edge of an inexpensive grade ofloosely woven Indian head cotton fabric, detector 8, will ravel out muchmore easily than the pinked edge of the poplin fabric-material, detector8a, used for the backing of the colored swatches: The mechanicalpounding of most formulas used by commercial laund-ries would make itimpossible to tell whether or not the lower edge of the detector 8hadbeen pinked prior to washing. The pinkededge of detector 8a, however,persists.

Time would exert a decided influence-on the degree of ravelling of bothserrate-d edges. If the mechanicalad' tion of two different washers isbeingtested, formula time should be comparable. The degree to whichoverloading restricts mechanical pounding can be evaluated bydeliberately overloading and underloading two different pockets of thesame washer, and including a detector in each pocket.

The chart shown 'below will serve as a guide in evalu- 2. ion. (2) Mildmechanical action.

(3) Normal mechanical action.

(4) Severe mechanical action.

Edge is frayed, pinking effects barely lsible v Cannot tell that theedge was pinked.

Frayed edges longer than on A-3 above.

Very slight fraying;

similar to A-l.

The outline of the pinked edge is still visible.

The edges are badly frayed, pinking effects are barely visible. Similarto A-2 above.

By using pinked edges for the large cloth as well as the small cloth,the degree of rave'lling indicates the degree of mechanical action.

Assume that we have a tester from a medium soil Formula #2, in whichonly a little color loss" is observed in detector No. 7, i.e., a matchin row-#1 instead of row #3, Table XVIII. Also assume that both alkalineand temperature intensities are normal. That is, detector #4 shows amatch in row 3, Table XIV; detector #5 in row 5; detector #6, row 5 inTable XVII; and detector 8 shows conditions equivalent to row 1 in TableXIX above, thereby indicating mechanical action that is deficient. If,however, detectors *8 and 8a show'undue mechanical effects,- row 4,Table XIX, while detectors4, 5 and 7 are the same as shown above,detector 6 will show deficient alkalinity and show a match in row 3,Table XVII.

As described above, detectors are most useful in showing not only whathappens during a washing process, but give an indication of theintensity of these parameters. The following tables show five or sixdesirable goals ar-' ranged in rows for various types of Washingformulas. If Plochere cards are employed, it would be advisable to laythe cards out, side by side, as the following data is read.

In specifying a row in which the most desirable match will occur, it isnecessary to use fractional numbers. For example, row 2.5 is a colorbetween 2 and 3 for the heat detector 4 and would indicate washingtemperatures between F. and F.

The following Table XX is an example of a desirable set of color matchesfor detectors which result from operations as indicated in the tablesgiven below. The major parameters that are measured in detectors 1 to 8awill be as shown in Table XX.

Table XX Bleach Heat effects Alkaline Soil Mechanintensity removal icalaction Mild Normal Severe Detector l 1 2 a 4 5 6 7 s and 8a The mostdesirable row for- Light soil 2 2 2 2. 5 3. 0' 3. 0 B-2 2. 5 Mediumsoil. 3 3 3 3.0 4. 0 4. 0 C 3 3. 0 Heavy soil 4 4 4 3. 5 6.0 5. 5 D-4 3.5 Rewash or stain load. 5 5 5 3. 5 6.0 6.0 E-i 3.-5

1 Row refers torows 1-7 of Table XI, under detectors 1-3 respective 1y.2 Row refers to rows 1-4 of Table XIV for detector #4 and Table XVI fordetector #5. 3 Row refers to rows 1-7 of Table XVII for detector #6. 4Row refers to column and row designation on Table XVIII for detector #7.5 Row refers to rows 1-4 of Table XIX for detectors 8 and 8a.

ating mechanical effects. It was derived by using as a'comparativestandard 42 x 96 open pocket washers that turn at 22 r.p.m., [have 7"ribs, and were loadedwith 350 pounds of towels (clean dry weight).

Having selected the rows in which the best match is likely to occur, itwould be advantageousto select values that should not be exceeded in theevent the plant operator finds it necessary to increase the intensity ofhis wash- Table XXI Detectors 1 2 3 4 5 6 7 8 and 82.

Row Row Row Row Row Row Row Row Normal light soil--. 2 2 2 2. s a. 3. 013-2 2. Using more bleach 3. 5 3. 5 3. 5 2. 5 3. 0 3. 0 D2 2. 5 Usingmore alkali. 2 2 2 2. 5 3. 0 5. 0 B-,-4 2. 5 Using more heat- 2 2 2 3. 56. 0 3.0 B-Z-l 2. 5 Using more agitation. 2 2 2 2. 5 3.0 3.0 B-3 3. 5Using less heat with more alkali and agitation 2 2 2 2. O 1. 5 4. 5 B-23. 0

N0'rE.-Row designation as in Table XX. Fractional rows indicate a colormatch intermediate between rows, e.g., 2.5 means color intermediate thatof row 2 and that of row 3.

The parameters that are most likely to cause damage to fabrics arebleach, alkali, heat, and agitation, in the order shown above. Theoperator of a plant will select the least costly combination for hisparticular plant in order to achieve a desirable goal. For example, ifhis boiler capacity is limited, he could use the last combination inTable XXI shown above, to achieve the desired B-2 condition withdetector No. 7.

It may be that an exact color match with detector No. 7 may not beachieved, For this reason it is desirable to accumulate washed detectorsand compare them with each other, as well as with the color cards. Themethods used above can be applied to each of the various types offormulasmedium soil, heavy soil, and stain treatments. The desirabilityof employing detectors which mutually support each other in givingintelligence as to the operating conditions is illustrated by assumingunusual variations in formulas.

NOTE .Row designation as in Tables XX and XXI.

A casein point would be to assume that a supply house advocates low pHbleaching on medium soil formulas. The only way to achieve this is touse a milder alkali on the alkali suds bath, use more flushes prior tothe bleach bath, or add a low pH buffer (probably acid phosphate) to thebleach bath itself. The most desirable row combination for medium soilis shown below, along with the changes that will occur.

(1) The use of added flushes prior to the bleach bath would increase theintensity of the bleaching effect from row 3 to row 4 with detector 3 onTable XI. At the same time, temperature effects and mechanical actionwould increase, since the formula would require longer duration oftreatment.

(2) A milder alkali on the suds would cause an undesirable shift indetector 7 to condition C2 on Table XVIII. In this case the increasedstain removal powers of the low pH bleaching probably will not make upfor lower alkalinity on the suds bath, when fatty soil is being washed.However, such conditions may be desirable when doctor towels are beinglaundered.

' (3) This method of reducing alkalinity of the bleach bath allows thefatty stain removal powers of the original formula to remain undisturbedand still achieve a lower pH value during the bleach bath. The cost ofthe acid phosphate should be related to the savings due to lower rewashpercentages.

THE LAUNDERING PROCESS EMPLOYING THE TESTERS OF MY INVENTION Thesedetectors are used in combination to monitor the sudsing, rinsingfollowing the sudsing, bleaching, rinsing after bleaching, and scouringoff, to determine the efiect of alkalinity, temperature and time duringsudsing, the adequacy of the rinsing operation after sudsing, the efiectof the sudsing and rinsing upon the bleaching operation, the eifect ofpH, bleach concentration and quantity, temperature and time duringbleach, and the effect of rinsing and souring oif after bleach-in otherwords, of the significant parameters which determine the character ofthe washing operation.

Detectors 4 or 4 and 5, together with 6 and 7, 8 and 8a, monitor thelevel of the sudsing operation, to wit, whether insufficient, normal orexcessive.

As stated above, detector 4, if viewed in ordinary light, shows colorchanges if the temperature is abnormally low and substantially no changeat higher temperature. Detector 5, if viewed in ordinary light, showscolor changes if the temperature is abnormally high and shows no changeat lower temperatures. Together they will indicate, when viewed inordinary light, whether the temperature was abnormally low, normal orabnormally high.

Detector 4 may be used alone without using detector 5, This detector,when viewed under ultraviolet light the Wave length of which is 2537 A.or 36 00 A., will by its fluorescent color change, indicate whether thetemperature was abnormally low, normal or abnormally high.

Detector 6 will indicate whether the combination of alkalinity andtemperature which resulted was abnormally low, normal or abnormallyhigh. This detector will not tell whether the temperature or thealkalinity were abnormally low or abnormally high or normal throughoutthe whole time of the exposure of the detector. Thus a high temperatureand low alkalinity throughout the period of exposure may give the sameresult as low temperature and high alkalinity for like periods of time,or time may act in the same direction as alkalinity or temperature.

By using a combination of detector 4 viewed under ultraviolet light anddetector 6, or when using detectors 4 and 5 together, when viewed underordinary light, and also detector 6, the relative influence oftemperature and the combined effect of alkalinity and time may besegregated, and it may be determined whether alkalinity was abnormallylow, normal or excessive during the sudsing step.

To determine whether the alkalinity was abnormally low, normal orexcessively high during the entire period of exposure, one may usedetector 7, which shows color changes if both the alkalinity and thetemperature were abnormally low, or both normal, or both excessivelyhigh throughout the Whole period of exposure of the detector in thesudsing peration.

This, however, will not tell whether the test results obtained withdetectors 4, 5 and 6 were due either to the effect of temperature,alkalinity or time on the sudsing operation. To segregate whether timeis the influence,

detectors 8 and 8a are employed, as has been previously 25 together withdetectors 8 and 8a, as described above; The interpretation of otherconditions will be evident from the foregoing description.

As stated above, the intensity of the bleach is determined by the soilentering the bleaching step, and this depends on the sudsing operationsand the following rinsing operation prior to bleaching. The adequacy ofthe sudsing operation can be determined by the detectors 4, 5, 6 and 7,and 8 and 8a. As appears from the following, the bleaching operation isadversely affected by the excessive soil entering the bleach, and thismust be caused by the inadequacy of the sudsing and rinsing.

Detector No. -'1 will report whether intensity is low or normal, but notwhether it is excessive. It will not, however, report whether, ifabnormally low, bleach intensity is the result of an abnormally lowtemperature or time or bleach concentration; and if it reports thebleach intensity as normal, whether the bleach concentration, time andtemperature were mutually compensating to produce a normal bleachingeffect.

Detector No. 2 will determine whether the bleaching intensity is normalor excessively high, but will not distinguish between the-two.

Detector No. 3 will indicate whether the bleaching intensity isexcessive, but will not indicate whether this excessive bleach resultsfrom too high a bleach concentration, too high a temperature, or toolong a time, but will report only that the combined effect of theseparameters resulted in excessive bleaching action.

By using all three together, we can determine whether the bleachingintensity is normal, abnormally low, or abnormally high. It will not,however, give information as to the effect of the parameters whichinfluence the bleaching result, but will report the integrated effect ofall of the parameters acting during the bleaching operation.

To segregate the effect of these parameters, we use a fresh set ofdetectors at the start of the bleaching operation. FIG. 3 of the drawingshows an assembly consisting of detectors 4, 5, 6, 7, 8 and 8a. Byintroducing a second such set of alkali, time and temperature detectors,the intensity of each, or their conjoined action, will be monitoredduring the bleaching step. Normally, there will be a decided contrast inintensity between the two sets. The magnitude of these diiferences willprovide the reason for abnormalities in bleaching intensity.

Thus, if bleach intensity is abnormally low, two sets of detectors maybe used on future tests to determine the cause. The entire assembly FIG.1 will be referred to as set No. l, and the set shown in FIG. 3 as setNo. 2.

If set No. 1 shows normal alkalinity, time and temperature, and set No.2 shows very little change, it is clearly evident that a failure torinse out the soil loosened on the sudsing step caused the bleachingintensity to be low. However, if there is very little contrast betweenthe alkali, time and'temperature detectors of set No. 1 and set No. 2,it is proof that the sudsing step was deficient, and that alkalinity,time and temperature of the bleach bath was excessive. The reason thatthese conditions do not increase the overall bleaching intensity is thefact that bleach will be destroyed by the loosened soil, and thereby notbe available to alter the bleach sensitive detectors.

Variations in bleaching intensity on different sections of the sametowel, for example, may be noted by including square yard sections ofthe dyed fabric of detectors 1 and 2. A decided mottledeffect will beobserved when there is an attempt to carry out a sudsing and bleachingoperation simultaneously.

If the combined effects of soil and bleach are low, the green fabric of.detector 1 will have black areas. If excessive bleach is used, both thegreen and light blue fabric (detector 2) will be mottled in appearance.

The addition of square yard pieces of bleach-sensitive 2efabr-ic isunnecessary -tomonitor normal washing formulas. The combined use of setNo. 1 and set No. 2 is reserved for. conditions in which the bleachingintensity is unaccountably low.

If the sudsing operation was normal according to the report of detectors4 to 8a, and the detectors. 1. to 3. show an abnormal condition in thebleach, this abnormality may be the result. of an abnormality in theparameters of alkalinity of a bleach bath, and the temperature and time,and their levels during their conjoined action present during thebleaching operation.

OTHER USES In the previous discussion, I have described the use of mydetectors as indicators wherein they are structurally separated from thewash load byadding them in a tester to the wash load. However, it ispossible to combine them with the fabric to be washed, as by sewing themto the fabric. An alternative is to interweave them with the fabric'bydyeing theyarn with the dyes as described above.

Thus, as an example only, yarn dyeings have been prepared of threevatdyes used to detect bleaching intensity of detectors 1, 2 and 3, thusproducing three'yarn strands so dyed. It would be possible for a cottonmill to incorporate the three colors of detectors 1-3- into a stripe orhem of a towel. It would serve the very useful purpose of givinganindication of the bleaching intensity to which the towel has beensubjected.

The dark green detector 1 would turn black and remainthat way for thelife of the towel. The light blue detector 2 becomes colorless undernormal light after two or three stain removal treatments; especially ifthe pH of the bleach bath is low. However, the bleached yarn, which iscolorless under ordinary visuallight, will appear colored when viewedwith the aid of an ultraviolet lamp. The dark blue yarn detector 3 wouldserve as an excellent monitor in guarding against over-bleaching, andprobably be visible during the entire service life of the fabric. Theseyarns could be used to sew pocket seams, etc., on white cotton garments.They would be inconspicuous and serve as a monitor of'bleaching eifects.

A cotton mill or bleachery may find these yarns extremely valuable inmonitoring J-box bleaching. Commercial laundries that rent cotton goodsmay find it advantageous to request these yarns in stripe form ontowelling or in the selvage of cotton yardage. It would furnish proofthat the mill or bleachery has not prepared fabrics that were bleachedat low pH values.

These detectors may be employed as an aid in evaluating the comparativeefiiciency of two different washers or washing supplies.

Many textile chemists have pointed out the difficulty of evaluatingcomparative detergent efiiciency of two different washers or washingproducts.

It is necessary to exercise very careful control over the operators whosort and classify linens prior to sending them to the customer. In mostlaundries it is impractical to reject minor stains which are acceptableto the customer. It is necessary to rely upon the judgment of employeesin maintaining uniform quality. A constant quality standard must bemaintainedwhile stain treat percentages are being accumulated. Dailyvariations are quite large, and several. months are required toaccumulate data with statistical significance in evaluating thecomparative efiiciency of washers and detergents and washing formulas.Thus, it becomes apparent that the costof evaluating minor changes. ineither supplies or washing equipment would exceed that of the resultantsavings. Detectors can aid significantly in eliminating. trial and errormethods of intensifying parameters related to supplies or equipment.They are also an invaluable aid when the effluent from washing. baths istitrated for alkalinity, residual bleach', and .the like;

Detectors may be used to determine whether various 27 portions of thewasher vary in rinsing rates and bleaching intensity when all of thewater enters the machine from one end, instead of in the middle. Unevenbleaching intensity usually occurs, as evidenced by the mottledappearance of the detector fabric.

Dyeing for many years has been considered an art rather than a science.To a lesser degree, washing had followed the same pattern. A set ofrules regarding parameters that contribute to fabric damage had beenestablished. Detectors permit a quantitative evaluation of theseeffects. As an example: Dr. Pauline Berry Mack, editor of FellowshipReports (a monthly publication for Linen Supply Laundries), cautionsmembers about the damage caused by high temperature rinsing after thebleach bath-operation step No. 8, Formula No. 3; or operation step No.6, Formula No. 2. Detectors have demonstrated that the concentration ofbleach carried over into this step is so low that for all practicalpurposes it can be ignored. They have also shown that damage formerlyattributed to high temperature rinses following the bleach bath was farmore likely to be caused by the unevenness of bleaching intensity thanfrom the use of multiple suds washing formulas recommended by theAmerican Institute of Laundering.

Detectors have been used to monitor the intensity changes of bleachesother than hypochlorite. Both dichlorodimethylhydantoin andtrichlorocyanuric acid will alter all three of the bleach-sensitivefabrics in substantially the same way. The slower decomposition rate ofthese bleaches can be demonstrated by using a detector during andanother after the bleach bath.

Most oxygen bleaches do not affect the three test fabrics, detectors1-3. Formulations of oxone based on potassium monopersulfate do notalter the color of detectors 1-3, unless sufficient salt (NaCl) is addedto provide a hypochlorite ion. Even under these circumstances, the colorloss in detector 2 is very slight.

While I have described a particular embodiment of my invention forpurposes of illustration, it should be understood that variousmodifications and adaptations thereof may be made within the spirit ofthe invention, as set forth in the appended claims.

I claim:

1. A laundry tester for determining the intensity of a sudsing operationin a laundry process comprising:

(a) a cotton textile enclosed in a water-permeable and dye-impermeableplastic envelope, said textile being dyed with a dye classified by theColor Index No. 16,605 to a color substantially equivalent to a colorclassified as ISCC-NBS No. 248;

(b) an alkali-reaction intensity indicator comprising a wool textiledyed with a dye classified by Colour Index No. 45,100 to a colorsubstantially equivalent to a color classified as ISCC-NBS N0. 254;

(c) an alkali-reaction intensity indicator comprising a cotton textiledyed with a dye mixture composed of a dye classified as Colour Index No.30,925, containing minor amounts of dyes classified as Colour Index No.11,020 and Colour Index No. 19,555, to a color substantially equivalentto a color classified as ISCC- NBS No. 151; and

(d) a mechanical action indicator comprising a piece of cotton sheetingand a piece of poplin both pinked at their edges.

2. In the tester of claim 1, in which:

(a) said color equivalent to ISCC-NBS No. 248 color is a colorsubstantially equivalent to a color classifield as Plochere 388; and

(b) said ISCC NBS No. 254 color is a color substantially equivalent to acolor classified as Plochere 434; and

(c) said ISCC-NBS No. 151 color is a color substantially equivalent to acolor classified as Plochere 977.

3. In combination with the tester of claim 1, a temper- 28 atureindicator comprising a piece of paper colored with a paint pigmentedwith anhydrous chromium chloride.

4. In .the tester of ,claim 3, said paper having a color substantiallyequivalent to a color classified as a Merz and Paul color at Plate41-F-5.

5. In combination with the tester of claim 2, a temperature indicatorcomprising a piece of paper colored with a paint pigmented withanhydrous chromium chloride.

6. In the tester of claim 5, said painted paper having a colorsubstantially equivalent to a color classified as a Merz and Paul colorat Plate 41-F-5.

7. In combination with the tester of claim 1;

(a) a bleaching intensity indicator formed of a cotton textile dyed witha dye classified by the Color Index No. 59,850, to a color classified asISCC-NBS No.

(b) an alkali-reaction intensity indicator formed of a cotton textiledyed with a dye classified by the Colour Index No. 74,140, to a coloridentified by ISCC-NBS No. 168; and

(c) a bleaching intensity indicator formed of a cotton textile dyed witha dye classified by the Colour Index No. 73,065, to a color classifiedas ISCCNBS No. 194.

8. In the tester of claim 7, in which:

(a) said ISCC-NBS No. 145 color is a color substantially equivalent to acolor identified as Plochere 1034; and

(b) said ISCCNBS No. 169 color is a color substantially equivalent to acolor identified as Plochere 771; and

(c) said ISCC-NBS 'No. 194 color is a color substantially equivalent toa color identified as Plochere 625.

a 9. In the tester of claim 7, in which said ISCCNBS No. 145 color is acolor substantially equivalent to a color identified as Munsell 6.063.8/2.5, and said ISCC-NBS No. 169 color is substantially equivalent toa color identified as Munsell 6.0B 4.9/9.0, and said ISCO-NBS No. 194color is a color substantially equivalent to a color identified asMunsell 8.0PB 2.8/14.

10. A process of laundering comprising:

(a) mechanically agitating soiled wash in an aqueous alkali solution ofa detergent at an elevated temperature for a period of time in thepresence of a tester defined as in claim 5;

(b) withdrawing the alkali solution;

(0) rinsing said wash at an elevated temperature; and

(d) controlling the temperature during said washing such that (i) thetemperature-sensitive textile with an initial color of Plochere 388,referred to in (a) of claim 2, changes in color to give a color having ahigher Plochere number but less than a Plochere No. 451, when seen underultra-violet light; and

(ii) said paper referred to in claim 3 changes in color but has a colorintensity classified as a Merz and Paul color in Plates 43 to 46; and

(e) controlling the alkalinity (i) to substantially destroy the color ofthe textile referred to in (b) of claim 2; and

(ii) the color of said textile referred to in (c) of claim 2, changingto increase its Plochere number but to less than a Plochere No. 1094;and

(f) continuing said agitation for a time and with a degree of mechanicalagitation to substantially remove the pinking on the white cotton cloth,without entirely removing the pinking of said white poplin clothreferred to in (d) of claim 1.

11. A process of laundering, employing a sudsing and a bleaching step,which comprises:

(a) agitating soiled wash in an aqueous alkali solution of a detergentat an elevated temperature for a period of time in the presence of atester as defined in claim 8;

(b) withdrawing the alkali solution;

() rinsing said Wash and said tester at an elevated temperature;

(0.) adding a solution of a bleaching agent to said rinsed wash andtester;

(e) agitating said wash and tester in said bleaching solution at anelevated temperature and for a prolonged period of time;

(1) controlling the temperature such that (i) the temperature-sensitivetextile, referred to in (a) of claim 2, changes in color to give a colorhaving a higher Plochere number but less than Plochere 451 when seenunder ultra-violet light; and

(ii) said paper referred to in claim 3 changes in color but has a colorintensity classified as a Merz and Paul color in Plates 43 to 46; and

(g) controlling the alkalinity to substantially destroy the color of thetextile, referred to in (b) of claim 2, and the color of said textile,referred to in (c) of claim 2, changes to increase its Plochere numberto less than 1094; and

(h) controlling the bleach concentration, temperature and agitationduring the bleaching step to (i) change the color of the textile,referred to in (a) of claim 8, to a black color, and the textilereferred to in (b) of claim 8 to a higher Plochere number but less thanPlochere No. 776; and

(ii) change the color of the textile, referred to in (c) of claim 8, toa higher Plochere number but but less than Plochere No. 628; and

(i) continuing said sudsing and bleaching steps for a time sufficient toremove the pinking of said white cotton fabric without entirely removingthe pinking of the White poplin fabric.

12. In the process of claim 11, in which said Wash and tester areagitated with said bleaching solution in the presence of another testeras defined in claim 1, and in which the color changes in the textiles ofsaid other testers are substantially the same as the like-coloredtextiles of the first-mentioned testers.

13. In the process of claim 2, in which said wash and tester areagitated with said bleaching solution in the presence of another testeras defined in claim 1, and in I which the color changes in the textilesof said other testers are substantially the same as the like-coloredtextiles of the first-mentioned testers.

14. In the process of claim 3, in Which said Wash and tester areagitated with said bleaching solution in the presence of another testeras defined in claim 1, and in which the color changes in the textiles ofsaid other testers are substantially the same as the like-coloredtextiles of the first-mentioned testers.

15. In the process of claim 4, in which said Wash and tester areagitated with said bleaching solution in the presence of another testeras defined in claim 1, and in which the color changes in the textiles ofsaid other testers are substantially the same as the like-coloredtextiles of the first-mentioned testers.

16. In the process of claim 5, in which said Wash and tester areagitated with said bleaching solution in the References Cited in thefile of this patent UNITED STATES PATENTS 2,278,339 Vollmer Mar. 31,1942 2,308,087 Lappala Jan. 12, 1943 2,567,445 Parker Sept. 11, 19512,663,692 Corso et al Dec. 22, 1953 2,799,167 Loconti July 16, 19572,880,070 Gilbert et al. Mar. 31, 1959 Jordan Oct. 31, 1961 OTHERREFERENCES Better Laundering, Procter and Gamble, 1949, pp. 98109.

fI-Iydrion pH, 1958 Catalog of pHydrion.

1. A LAUNDRY TESTER FOR DETERMINING THE INTENSITY OF A SUDSING OPERATIONIN A LAUNDRY PROCESS COMPRISING: